OTTAWA — Canada's drug regulator approved Moderna's COVID-19 vaccine for infants and preschoolers Thursday, making it the first vaccine approved for that age group in the country.
Health Canada now says the Moderna vaccine can be given to young children between the ages of six months and five years old in doses one-quarter the size of that approved for adults.
"After a thorough and independent scientific review of the evidence, the department has determined that the vaccine is safe and effective at preventing COVID-19 in children between 6 months and 5 years of age," the department said in a statement posted to Twitter.
The National Advisory Committee on Immunization says the vaccine "may" be offered to children under 5. While serious illness among children is rare, the committee said the number of children hospitalized for COVID-19 shot up dramatically as the Omicron variant spread rampantly last winter.
"While most children in this age group have relatively mild disease, some do experience severe illness, especially those with underlying medical conditions," said NACI chair Dr. Shelley Deeks in a statement Thursday.
The average monthly rate young children hospitalized because of COVID-19 increased from 1.4 per 100,000 children under five in the first two years of the pandemic to 15.9 per 100,000 in the first three months of 2022.
Health Canada said it will continue to keep a close on the safety of the vaccine, and has required Moderna to provide updated data on both the safety and effectiveness of the vaccine.
In its decision posted on the Health Canada website, the agency said Phase 3 trial results for the drug show the immune response in children six months to five years old was comparable to Moderna's vaccine for 18 to 25-year-olds.
The approval expands COVID-19 vaccine eligibility to nearly two million children in Canada, though where and when the vaccine will be given to kids will be determined by provinces.
In Moderna's trials two doses of the child-sized vaccine were given about four weeks apart, but NACI recommends waiting eight week between shots.
NACI also recommends a third dose for immunocompromised children, with a four to eight week wait between injections.
For now, the committee says the COVID-19 vaccine should not be given to babies, toddlers or preschoolers at the same time as vaccines for other illnesses to help identify any potential reactions.
Health Canada said there were no safety concerns identified in the study. The most common reactions were similar to the ones kids experience for other pediatric vaccines, like pain at the site, sleepiness and loss of appetite.
Less commonly, some kids got a mild to moderate fever, swelling at the injection site, nausea, tender lymph nodes under the arm, headaches and muscle aches.
Health Canada said there are still some uncertainties about the vaccine because it's new and there's no long-term data available yet. For example, there's little data about the risk of very rare reactions like myocarditis, a swelling of heart tissue, though no cases came up in the trials.
There is also more to learn about the safety and effectiveness of the vaccine in young children with other health conditions or who are immunocompromised, the documents said.
The United States approved Moderna and Pfizer's pediatric COVID-19 vaccines last month, and so far have immunized 267,000 children in that age group as of July 8.
Pfizer's pediatric COVID-19 vaccine for young children between six-months and five-years old was submitted to Health Canada last month and is still under review.
This report by The Canadian Press was first published July 14, 2022.
Laura Osman, The Canadian Press